Biological test results from a Texas Department of State Health Services investigation in the tiny Denton County town of DISH indicate that residents’ exposure to certain contaminants was not greater than that of the general U.S. population.

A large complex of natural-gas compressors and pipelines converge in the town of 180 people. In response to community concerns about potential health effects of natural gas drilling, health officials collected biological samples from 28 DISH residents in late January to determine whether the levels of Volatile Organic Compounds, or VOCs, in their blood were higher than those measured in the broader population.

“In DISH, we found no pattern to our test results indicating community-wide exposure to any of these contaminants,” said Dr. Carrie Bradford, the DSHS toxicologist who led the investigation.

“We were looking to see whether a single contaminant or a handful of contaminants were notably elevated in many or all of the people we tested. We didn’t find that pattern in DISH.”

Health officials paid particular attention to benzene because of its association with natural gas wells. The only residents who had higher levels of benzene in their blood were smokers, the report showed. Because cigarette smoke contains benzene, finding it in smokers’ blood is not unusual.

Some residents had test results that were at or below expected levels for various VOCs. Others had results that were slightly higher than the levels found in the U.S. population data. However, the type of slightly elevated VOC varied considerably from individual to individual, indicating no particular pattern. Many of these compounds are found in a wide array of commonly used products.

While the purpose of the investigation was to determine whether people were being exposed to specific contaminants, it does not determine specific exposure sources, nor does it provide an assessment of possible long-term exposures.

"In the past three weeks, the state has provided answers that can unequivocally assure residents of DISH and the Barnett Shale-area-at-large of the safety of natural gas operations in the region and eliminate concerns about benzene levels in their air and blood," said Ed Ireland, Ph. D, executive director of the Barnett Shale Energy Education Council.

Health officials will hold a community meeting to discuss the results at the DISH town hall from 7 to 8:30 p.m. May 18. They also will be available from 5 to 6:30 p.m. to speak with residents. The full DISH exposure investigation report can be found at http://www.dshs.state.tx.us/epitox/assess.shtm.